Before the 2013 season, it would be difficult to say what was Red Sox pitcher Koji Uehara’s most remarkable accomplishment.

A forgettable reliever with the Orioles in 2009 and 2010, Uehara opted to test free agency, got no other bidders and wound up signing back with Baltimore for a $2 million pay cut. Uehara took his game to another level in 2011, but his greatest contribution to the Orioles was being on the other end of a trading-deadline deal with the Rangers that brought back Tommy Hunter and Chris Davis (who this season set a franchise single-season homer record). By the end of the 2012 campaign, Uehara was on the move again, testing free agency a second time, and for a modest $425,000 raise he moved to Boston.

The rest, as they say, is history, and the only question left to answer in 2013 is whether Uehara can put his final signature on a world championship, the way Mariano Rivera or Rollie Fingers or other great relievers have in the past.

Consider this about the 38-year old righty, whose primary weapons are a fastball and splitter: in four seasons with his two previous employers, he registered a total of 14 saves. He has always had sensational command, but in 2013 his 1.09 ERA was forged on allowing only nine walks in 74.1 innings. That’s nine walks in 73 appearances.

The 21 regular-season saves don’t say much until you remember he didn’t become the club’s regular closer until late June.

Once that happened, he was almost untouchable (note that the walkoff run he gave up to Tampa Bay in the ALDS was just the second run he has allowed in 3 ½ months, and that at one point this season he retired 37-consecutive batters, the equivalent of a perfect game plus 10).

If you combine the regular season and playoffs, entering yesterday he has allowed two earned runs over his last 44 appearances, which may be the greatest such streak by any reliever in baseball history.

How dominant is Uehara? Four times in September he threw double-digit pitches in an outing and allowed the opposition one ball. Not one run or hit, one ball. He hasn’t walked a batter since Aug. 3. When the Tigers got two hits off Uehara in Game 1 of the series, it was just the second time he had allowed multiple baserunners in an outing since July 6.

You can’t get any more dominant than that, and what’s most incredible is that so many baseball fans are only learning his name now. In a season of Miguel Cabrera’s power, Yasiel Puig’s exuberance and Clayton Kershaw’s brilliance, Uehara has been the phoenix and quite possibly the best story, one that could lead to Boston’s third world championship this decade and, at $4.25 million, a bargain for the ages.

ODDS AND ENDS: Carlos Beltran in a Yankees uniform? Don’t be surprised. But as good as he has been in October, is a player with bad knees who will turn 37 in April the right way to go for a team that already has more than its share of players on the downside of their careers?

While we’re on the topic of Beltran, the Cardinals outfielder took some shots at his Dodger counterpart Yasiel Puig for the outfielder’s excessive celebrations during Thursday’s game. My take on this stuff? When it’s your team, you love the enthusiasm, but when the opposition does it, you hate it. Objectively speaking, if it pumps your team up and gets your teammates to play better, you do it and let the opposition worry about getting you out. Beltran has never been one to celebrate to excess so it’s no surprise that a player of Puig’s emotion would rub him the wrong way, but the best revenge is simply to win the game.

We will get more into free-agency options in future columns, but one player drawing a lot of interest (in rumors anyway) who seems best avoided is Braves catcher Brian McCann. McCann will turn 30 in February, but appears older than that on the field; his RBIs have declined four consecutive seasons and games played the last three. McCann is still good for 20 homers a season, but his numbers are beginning to resemble Jeff Francoeur: his on-base percentage this year was a sorry .300 and his doubles have gone down five consecutive years (from a peak of 42 in 2008 to an anemic 13 this year). McCann also appeared to peak defensively five years ago (when he had a DWAR of 1.6) making any long-term investment questionable at best.